Stitch selector means for automatic zigzag machines



Oct. 10, .1961 MASAYOSHI YASUI STITCH SELECTOR MEANS FOR AUTOMATIC ZIGZAG MACHINES R./ M mm I/ a W W M M Original Filed Feb. 21, 1955 3,003,442 STITCH SELECTOR MEANS FOR AUTOMATIC ZIGZAG MACHINES Masayoshi Yasui, Nagoya, Japan, assignor to Nippon Sewing Machine Mfg. Co., Ltd, Nagoya, Japan, a corporation of Japan Continuation of application Ser. No. 489,513, Feb. 21, 1955. This application July 11, 1958, Ser. No. 748,574 Claims priority, application Japan Dec. 16, 1954 7 Claims. (Cl. 112-158) This invention relates to a structurally and functionally improved sewing machine mechanism.

This application is a continuation of my prior application for United States Letters Patent Serial No. 489,513, filed on February 21, 1955, now abandoned.

It is a primary object of the invention to furnish an assembly by means of which the operation of the sewing machine mechanism may be controlled in an improved manner to produce various types of ornamental and decorative stitches.

A further object is that of designing a mechanism which will include relatively few parts, each individually simple and rugged in construction and which parts may be readily assembled and combined with the structure of a sewing machine to furnish a desirable mechanism functioning over long periods of time with freedom from all difficulties.

With these and other objects in mind, reference is had to the attached sheet of drawings illustrating one practical embodiment of the invention, and in which:

FIG. 1 is a vertical sectional view of a portion of a sewing machine, showing the control mechanism for varying the stitch patterns;

FIG. 2 is a view similar to that of FIG. 1, but illustrating the parts shifted to a difierent position;

' FIG. 3 is a sectional plan view taken along line III-III 'in the direction of the arrows of FIG. 1;

FIG. 4 is a transverse sectional view taken along line lVIV in the direction of the arrows of FIG. 2; and

FIG. 5 is a sectional plan view taken along the line V--V and in the direction of the arrows in FIG. 1.

In the drawing, there is shown a portion of an upper housing 1 of an automatic zig-zag sewing machine, in which housing an upper drive shaft 2 is journaled. A cam shaft 3 is rotatably disposed in said housing transversely of drive shaft 2 and is driven by the latter at a predetermined speed relative thereto through gears 2a and 3a. Fixed to cam shaft 3 is a cam assembly, generally designated by numeral 4, which in the illustrated embodiment consists of a group of cam discs 4a to 43 mounted longitudinally of the cam shaft for rotation therewith. The cam discs are fixed to one another, as by a dowel pin or bolt 4', to prevent relative rotation therebetween.

Extending parallel to cam shaft 3 and also journaled in housing 1 is a shaft 10 to which is attached a transversely extending cam feeler or follower 5. Shaft 10 is supported in a sleeve 7 for sliding movement longitudinally thereof; relative rotation between shaft 10 and sleeve 7 being prevented by having the follower 5 extend through a slot 11 in the sleeve. Sleeve 7 in turn is supported solely for rotation by a frame 6 fixed to the housing. A rack 9 is provided on shaft 10 adjacent one end thereof, access to the rack being bad through an opening 14 in sleeve 7.

Sleeve 7 has afiixed thereto a ring member 16 provided with a transversely projecting lug or crank element 15. A rocking lever or plate 18 is pivotally mounted at 17 in the housing and interposed between lug 15 and a pitman or other connecting element 20. So arranged, it cooperates with lug 15 through having its face engaged by "the latter. Theconnection between plate 18 and the pitman is effected by the latter bearing against the oppo- 3,003,442 Patented Oct. 10, 1961 ice site face of the plate. The pitman is connected to the rockingly mounted needle bar of the sewing machine in any suitable manner (not shown).

A selector shaft 12 is vertically disposed in housing 1 and is slidably and rotatably supported by frame 6. Intermediate its ends, selector shaft 12 is provided with a pinion 13 extending through opening 14 to mesh with rack 9 on follower shaft 10. Selector shaft 12 protrudes through an opening 12' in the upper surface of housing 1, and a manipulating cap or knob 28 is fixed to the upper end of shaft 12, such as set screw 23'.

Attached to selector shaft 12 intermediate its ends, adjacent and slightly below pinion 13 is a deflector cone 21. A compression spring 22 surrounds the lower portion of shaft 12. One end of this spring abuts against the lower edge of cone 21 and the other end of the spring bears against a portion of frame 6. Spring 22 thus urges shaft 12 upwardly relative to the housing.

A guide member 24, provided with a number of circumferentially spaced radial slots 23, is mounted upon the lower end of selector shaft 12. A screw or similar guide element 25 (FIG. 5) is fixed in frame 6 and is provided with an end portion or tip 26 extending toward selector shaft 12 and guide member 24. Tip 26 is so dimensioned as to be receivable within any of slots 23, and thus serves to lock and prevent rotation of shaft 12 when the latter is in the position illustrated in FIG. 1, i.e., when the sewing machine is being operated. Nut 27 limits upward movement of shaft 12.

Cam finger or follower 5, during the operation of the sewing machine, assumes the position shown in FIG. 1 and contacts the periphery of one of cam discs 4a to 4 As drive shaft 2 rotates, cam shaft 3 and cam assembly 4 rotate in synchronism therewith. A rocking motion is, therefore, imparted to finger 5 corresponding to the peripheral characteristics or contours of the particular cam disc with which the follower is engaged.

The rocking motion imparted to finger 5 is transmitted to shaft 10, sleeve 7, and ring member 16, and from the latter through crank 15, rocking plate 18, and pitman or link 20 to the rockingly mounted needle bar of the sewing machine. The needle bar, therefore, performs stitching movements corresponding to the motion of follower 5 as determined by the respective contours of cam discs 4a to 4f, as that follower reciprocates. A spring (not shown) is operatively connected to transfer link 20 to urge the latter toward and into engagement with rocking plate or link 18, thereby ensuring that finger 5 is normally retained in operative contact with the peripheral surfaces of that one of said cam discs in line with which it is disposed.

When it is desired to change the stitch patterns produced by the needle bar, it is merely necessary to push down on knob or cap 28 to depress selector shaft 12. As shaft 12 moves downwardly, cone 21 comes into engagement with projection or crank 15 and cams the latter (to the left in the drawing) from the position of FIG. 1 to the position of FIG. 2. Thus, a clockwise rotation is imparted to finger 5, disengaging it from the periphery of a cam disc and swinging it to a position at which it clears the edges of all the cams.

Simultaneously, due to the downward movement of shaft 12, guide member 24 is now located in the position shown in FIG. 2, so that the end or tip 26 of guide screw 25 no longer projects into any slot 23. This unlocks shaft 12 so it may be turned by rotation of knob 28, which results in a longitudinal displacement of rack 9 by pinion 13 and thus in a sliding movement of shaft 10 in sleeve 7. Accordingly, finger or follower 5 is shifted in a direction parallel to the longitudinal axis of shaft 3.

As soon as finger 5 traverses the cam assembly and reaches a position opposite the desired one of cam discs 4a to 4 knob 28 is released to permit spring 22 to push shaft 12 outwardly. As cone 21 moves up, lug or follower 15 is returned, under the influence of the spring connected to pitrnan or link 20, from the position of FIG. 2 to the position as shown in FIG. 1. Cam finger is correspondingly brought into engagement with the periphery of one of the cam discs. End 26 of screw 25 again engages in one of slots 23 due to the upward movement of guide member 24 to prevent rotation of shaft 12. The stitching operation, involving a new pattern, may then commence.

In order to enable the operator to select any particular cam disc or to determine with which of the cam discs finger 5 engages at any particular time, a series of graduations or indicia (not shown) may be provided on housing 1 to cooperate with a suitable pointer (not shown) on knob 28, or vice versa.

However, a further refinement is provided by the present invention to insure correct operation of the cam selector mechanism. Should knob 28 be released when cam finger 5 is above and between two of the cam discs, selector shaft 12 will not be returned to its normal uppelmost position by spring 22 because end 26 of screw 25 will rest against the upper surface of a solid portion of guide member 24 rather than fit into one of slots 23.

In such a case, cam follower 5 would not come in contact with any of the cam discs because cone 21 would still prevent return of crank to its operative position. The machine would, therefore, remain inoperative. This construction not only insures that finger 5 will always be in contact with only one cam disc at a time, but also eliminates the possibility of error in the selection of the desired cam disc.

It will, therefore, be obvious that the cam selector mechanism enables the operator to choose the desired stitching pattern by simply grasping with one hand knob 28 and depressing it. Thereupon by rotation, the indicator (not shown), which may be constructed so as to be readily viewable from a sitting position in front of the sewing machine, will register the fact that the retracted finger 5 is opposite the desired cam disc. Subsequent release of knob 28 then moves finger 5 into engagement with that cam disc.

By the present invention, it becomes possible to change stitching patterns even while drive shaft 2 and cam shaft 3 are rotating. Thus, as soon as finger 5 is retracted from one of the cam discs by depression of knob 28, the driving connection between shaft 2 and the needle bar is interrupted, and the latter will not be rocked even though shaft 2 still rotates. As soon as knob 28 is released, finger 5 reengages one of the cam discs and the needle bar is correspondingly shifted.

This is especially advantageous in the case of electrically driven sewing machines employed to perform a series of sequential stitching or sewing operations. With the use of the present invention, it is unnecessary to shut oi the drive motor each time a new stitch pattern is desired or each time another article is to be sewed, be it with the same or with a dilferent stitch pattern as that employed for the previous article. Thus, a considerable saving of time will be realized as well as greater economies in operation and reduction of worker fatigue.

It is, of course, apparent that a number of modifications of the disclosed embodiment of the invention are possible without involving a departure from the spirit of the invention. For example, by the provision of suitable intermediate gearing between, or in lieu of rack 9 and pinion 13, the feeler retraction and shifting functions may be accomplished by a simple rectilinear movement of selector shaft 12. Likewise, these two functions may be accomplished by a simple rotary movement of shaft 12 if a suitable linkage, such as a crank or a ratchet and pawl mechanism, were substituted for deflector cone 21.

It is, moreover, not intended to confine the cam assembly to any specific number of cam discs, variations in the number of discs employed depending solely on the types of stitching patterns to be produced. If desired, the discs need not be fixed on cam shaft 3, but may be loosely supported relative thereto, suitable clutch means being associated with each disc to connect the latter to the cam shaft in accordance with the operation and orientation of selector shaft 12.

A further modification of the present invention permits of connecting the cam selector mechanism to the feed mechanism of the sewing machine rather than to the needle bar. Alternatively, the selector mechanism may be connected to both the needle bar and to the feed mechanism or two separate but intercoordinated cam systems may be provided, one of them being connected to the needle bar and one to the feed mechanism.

The number of stitching patterns available to an operator of a sewing machine embodying the invention will, therefore, be seen to be almost unlimited. The amplitudes of the stitching motions are, of course, regulated by conventional means (not shown).

Accordingly, there has been provided in accordance with the present invention, an automatic zig-zag sewing machine having a needle bar, a drive shaft, and a mechanism for operatively interconnecting said drive shaft with said needle bar to transform motion of said drive shaft into desired stitching motion of said needle bar. This mechanism comprises a plurality of cams operable by said drive shaft, each of said cams having a surface contour corresponding to a respective stitching pattern. A follower normally engaging one of said cams is connected to impart to said needle bar a motion corresponding to the contour of the elected cam. Manipulating means are operatively connected to said follower and actuatable to disengage the latter from said cams and to move said follower to a position opposite another one of said cams, whereby upon deactivation of said manipulating means, said follower engages another of said cams.

Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously, numerous changes in construction and rearrangements of the parts may be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. A pattern selector assembly for use with a sewing machine to cause the stitching mechanism of the same to move in a zig-zag manner; comprising a cam shaft, cam means on said cam shaft and presenting a plurality of different cam surfaces, each of said surfaces corresponding to a predetermined, dififerent stitch pattern, a frame, a sleeve having a lateral opening adjacent one end and rotatably supported by said frame, a lug fixed to said sleeve and projecting transversely therefrom, a finger shaft disposed within said sleeve for rotation therewith and for sliding longitudinal movement relative to said sleeve, a rack disposed on said finger shaft adjacent said lateral opening, a cam contacting finger projecting substantially transversely of said finger shaft externally of said sleeve and toward said cam means, said finger being normally in contact with one of said cam surfaces, a selector shaft supported by said frame for rectilinear and rotary movement relative thereto, a pinion on said selector shaft and meshing with said rack through said lateral opening, and a camming cone on said selector shaft and cngageable with said lug, whereby, upon rectilinear movement of said selector shaft in one direction, said cone engages said lug and displaces the latter to rotate said sleeve and said finger shaft, thereby retracting said finger from said one surface, and, upon rotary movement of said selector shaft, said finger shaft slides 1ongitudinally within said sleeve, thereby displacing said finger from a position opposite said one cam surface to a position opposite another of said cam surfaces, subsequent rectilinear movement of said selector shaft in another direction disengaging said cone from said lug and permitting said finger to be brought into contact with said other cam surface.

2. A mechanism according to claim 1, further comprising resilient means engaging both said selector shaft and said frame to bias said selector shaft in said other direction of rectilinear movement thereof.

3. A mechanism according to claim 1, said cam means comprising a plurality of cam discs fixed on said cam shaft in side by side relation and longitudinally of said cam shaft.

4. A mechanism according to claim 1, further including guide means operatively connected to said selector shaft and coordinated with the locations of said cam surfaces for restraining rectilinear movement of said selector shaft in said other direction upon displacement of said finger to a position opposite more than one of said surfaces.

5. A mechanism according to claim 1, further including gear means on said cam shaft for connection to the drive means of said sewing machine.

6. A pattern selector assembly for use with a sewing machine to cause the stitching mechanism of the same to move in a zig-zag manner; comprising cam means presenting a plurality of different cam surfaces, each of said surfaces corresponding to a predetermined, different stitch pattern, a frame, a sleeve rotatably supported by said frame and having a lateral opening intermediate its ends, a lug fixed to said sleeve and projecting therefrom, a finger shaft disposed within said sleeve for rotation therewith and for sliding longitudinal movement relative to said sleeve, a rack disposed on said finger shaft adjacent said lateral opening, a cam contacting finger projecting from said finger shaft externally of said sleeve and toward said cam means, said finger being normally in contact with one of said cam surfaces, a selector shaft supported by said frame for rectilinear and rotary movement relative thereto, a pinion on said selector shaft and interconnected with said rack through said lateral opening, and deflecting means on said selector shaft and engageable with said lug, whereby, upon rectilinear movement of said selector shaft in one direction, said deflecting means is brought into engagement with said lug to displace the latter and to thus rotate said sleeve and said finger shaft, thereby retracting said finger from said one surface, and upon rotary movement of said selector shaft, said finger shaft slides longitudinally within said sleeve, thereby displacing said finger from a position opposite said one cam surface to a position opposite another of said cam surfaces, subsequent rectilinear movement of said selector shaft in a direction opposite to said one direction causing disengagement of said deflecting means from said lug and permitting said finger to be brought into contact with said other cam surface.

7. For use with a sewing machine having a member to be moved, a rotatable drive shaft for effecting movement of said member, a rotatably mounted cam shaft, means for coupling said drive and cam shafts for simultaneous rotation, a series of cams fixedly secured to said cam shaft to turn therewith, a follower shaft supported to extend parallel to said cam shaft, a follower to selectively engage the surfaces of the individual cams, said follower being mounted by said follower shaft, a rack connected to move axially with said follower shaft, a sleeve slidably enclosing said follower shaft, means for mounting said sleeve solely for rotation, said sleeve having an opening in line with said rack and a slot through which said follower extends, a selector shaft, means for movably mounting the same for rotation and axial shifting with respect to said follower, a pinion afiixed to said selector shaft and extending through the sleeve opening into engagement with said rack to cause reciprocation of said follower-mounting shaft as said selector shaft turns, means for rocking said follower out of engagement with a cam, means carried by said selector shaft to engage and operate said rocking means as said selector shaft is axially shifted, and an element operatively connected to said follower to reciprocate as the latter rocks and thus impart lateral movement to said member.

References Cited in the file of this patent UNITED STATES PATENTS 2,005,070 Bitzer June 18, 1935 2,007,863 Jenni July 9, 1935 2,377,777 Hale June 5, 1945 2,590,907 Van Tuyl et al. Apr. 1, 1952 2,593,778 Harris Nov. 9, 1954 2,832,302 Gegauf Apr. 29, 1958 2,862,468 Johnson Dec. 2, 1958 2,906,219 Vigorelli Sept. 29, 1959 FOREIGN PATENTS 19,184 Great Britain Sept. 12, 1908 1,095,914 France Dec. 29, 1954 

